FSi was the mechanical and fire protection engineer for the King County Metro South Annex Interim Base. The project was originally designed to temporarily serve staff and buses until the South Base was expanded with permanent buildings. We designed the building and systems to provide a minimum five-year life, balancing sustainability with a tight budget for the temporary building. The project demolished an existing building and added maintenance facilities and 25,000 sf of offices. The site includes six maintenance bays, a steam bay for cleaning buses, and an N+1 oil/water separator system.
The new fire protection system covers a wide range of occupancies and classification hazards. The simplest fire protection systems serve the base’s offices. The most complex protects the maintenance building, which includes battery storage and more than 2,000 gallons of flammable liquids such as windshield wiper fluid and motor oil. We designed the maintenance building’s fire protection system to strict FM Global standards, providing a high level of protection for workers and property.
The project balanced a limited first-cost budget with the County’s ambitious sustainability goals. We provided in-depth LCCA and energy modeling to determine the feasibility of designing to LEED Platinum and the most sustainable design options over the building’s life.
While the project was being constructed, the County identified a long-term use for the Interim Base. The base infrastructure was subsequently electrified, to support an electric bus fleet.
